As a conventional technique of compensating for non-linear distortions that are generated in a transmission power amplifying unit used for radio communications, known is that used in feedforward linear compensated amplifying equipment disclosed in Japanese Patent Non-Examined Publication No. 10-270950. This equipment employs a method of the following steps: extracting in its non-liner distortion extractor a non-linear distortion component generated in its main power amplifier; amplifying the non-linear distortion component in its auxiliary power amplifier; and suppressing the non-linear distortion component of a transmission signal by adding the extracted component to an output signal from the main power amplifier so that the two signals are in opposite phase.
However, this conventional linear compensated amplifying equipment has a problem that it requires an auxiliary power amplifier capable of linear amplification and thus efficiency of power utilization in the transmission power amplifying unit is considerably reduced.